disable the assembly for fast unaligned stores. indeed, there is a strange bug that is triggered by this code:
disable the assembly for fast unaligned stores. indeed, there is a strange bug that is triggered by this code:

#include<Eigen/Core>

int main()
{
  Eigen::Matrix4f m;
  m <<1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16;
  m.col(0).swap(m.col(1));
  std::cout << m << std::endl;
}

when the fast unaligned stores are used, the column is copied instead of being swapped.

cjntaylor/eigen,pthulhu/eigen,pthulhu/eigen,cjntaylor/eigen,cjntaylor/eigen,pthulhu/eigen,pthulhu/eigen,pthulhu/eigen,cjntaylor/eigen